block: bio_iov_iter_get_pages: fix size of last iovec
authorMartin Wilck <mwilck@suse.com>
Wed, 25 Jul 2018 21:15:07 +0000 (23:15 +0200)
committerJens Axboe <axboe@kernel.dk>
Thu, 26 Jul 2018 17:52:29 +0000 (11:52 -0600)
commitb403ea2404889e1227812fa9657667a1deb9c694
treebbe37dba31a278aaaa897261576248d51e5dc7ff
parent78e18063a9696c508dc95581fb8ec1aee539c4ee
block: bio_iov_iter_get_pages: fix size of last iovec

If the last page of the bio is not "full", the length of the last
vector slot needs to be corrected. This slot has the index
(bio->bi_vcnt - 1), but only in bio->bi_io_vec. In the "bv" helper
array, which is shifted by the value of bio->bi_vcnt at function
invocation, the correct index is (nr_pages - 1).

v2: improved readability following suggestions from Ming Lei.
v3: followed a formatting suggestion from Christoph Hellwig.

Fixes: 2cefe4dbaadf ("block: add bio_iov_iter_get_pages()")
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
block/bio.c